Eh up friends!

 

Had my 2001 Mk. 1 Octy VRs for 4 years now. Running a Stage 1 Revo remap, done just after purchase, with a panel filter, Forge re-circ valve, and stainless exhaust. All very mild, and the car has been totally reliable and run brilliantly over my tenure, going from 80k miles to it's current 140k. Serviced regularly, Mobil 1 Oil etc.

 

Anyway. Having owned her for so long, I am as 'in tune' with her, as a Father might be with his children

 

I know every little noise, foible, ways, and manners of her running. I am SURE many of you know what I mean! For example, if even the slightest thing changes, we know straight away!

 

 

I don't think this is a huge problem at all, and I am probably posting more to get a confirmation of my thoughts, more than anything else? But basically, a couple of weeks ago, I was driving my normal route home late one evening. It was a cool night, 11 degrees according to the temperature readout, and I drove home in my normal fashion. I live about 2 miles from the motorway, so I come off at the motorway junction, and then drive fairly sedately to my house, allowing the engine and turbo to cool off a bit after a motorway run. I then give it 30 seconds or so of idle, and shut her down.

 

On this occasion two weeks ago, and on several occasions since, after shut-down, the radiator fan has kept going for about 5 minutes or so. This has NEVER happened in the 4 years of ownership, even in the middle of summer. I've also noticed it running when I park up after other journeys too, even if I have been driving in a fairly sedate manner.

 

The coolant was replaced last summer, and the temperature gauge never deviates from it's usual straight-up, 90 degrees C position at any time. The car doesn't feel or smell like it's running any hotter than normal, and she is running as perfectly as ever.

 

 

So....I am inclined to think that it's just a possible fault with the radiator temperature sensor which operates the radiator fans?

 

The question is - firstly, where is it located, and secondly - is it a separate sensor from the sensor which feeds the instrument panel readout? If it is the same sensor for both, then I am puzzled as to why the gauge reads the usual temparature but the fans are now cutting in when they didn't before.

 

Does anyone have any comment / help on this please?

 

As always, thanks in advance!

 

 

It might be worth checking what the ECU thinks is the actual coolant temperature as the sensor is a 4 pin one...one reading for the dash and another for the ECU

 

Or could be the obvious...dicky fan switch?

Edited 4 October, 201411 yr by Liverpool-Lad

Ah cheers, interesting.....the thick plottens, as they say

 

So, there is a single CTS which feeds both the dash and the ECU? Yes of course, I was thinking along the lines of 'older cars' where the CTS was just connected to a relay which turned the fans on and off. But on our cars, it tells the ECU, which then in turn tells another switch / relay to operate? Is that correct?

 

Or is this 'fan switch' you've mentioned something else entirely that I am missing?
 

Cheers

Yep, might be worth checking its the correct green one also.  If you loook under the bonnet its on the right hand side of the engine under the plastic cover if you follow the radiator hose back towards the bulkhead

Smashing, cheers my friend. That gives me a place to start to look!

 

I'll post back here after